Installation and service bulletins from our technical team — the things that come back to bite a crew on a callback. Print them, keep them on the truck, or pass them to your installers. New notices are posted here as they come up, and go out to our contractor list by email.
Check the factory jumpers before your next install
GE air handler control boards ship with factory-installed jumpers on the low-voltage terminal strip. Whether a jumper stays in or comes out depends on the air handler type and what it is paired with — and getting it wrong is the single most common cause of short cycling, no ramp-down, and backwards heating/cooling changeover on heat pump systems.
| ECM air handler + heat pump | Remove the DS / R / O jumper |
|---|---|
| ECM air handler + AC | Leave the DS / R / O jumper in |
| Variable Speed + heat pump | Remove the O–R jumper |
| Variable Speed + AC | Leave the O–R jumper in |
The full notice also covers the DS terminal on Variable Speed units (dehumidification air volume — three options) and why removing the Y1 / Y2 jumper and wiring it as a true two-stage system gets you the full compressor and blower ramping profile.
Already have systems in the field? If a heat pump is short cycling, not ramping down, or showing incorrect changeover — check these jumpers first. It is usually this.
Stuck on a specific job? Call the counter at (770) 363-3124, Monday to Friday 7:00–5:00. We would rather talk it through than have you drive back out.